广西涠洲岛沉凝灰岩土壤粘粒矿物的研究

用X射线衍射分析和电子显微镜分析,对涠洲岛沉凝灰岩母质发育土壤的两个典型剖面八个土样的粘粒矿物进行分析研究。结果表明,离火山口距离不同的两个剖面土壤粘粒矿物组成不同,1号剖面以2:1型粘粒矿物为主,2号剖面则以1:1型粘粒矿物为主;结合其它分析结果,讨论了两个剖面土壤粘粒矿物组成不同的原因、对土壤有关特性的影响及其与土壤形成和分类的关系。     

Diatom Thalassiosira weissflogii in oligotrophic versus eutrophic culture: models and ultrastructure

Populations of marine diatom Thalassiosira weissflogii were grown in continuous cultures enriched with f/2 medium. One of the two contrasting cultures (‘eutrophic’) received 5.6 times more nutrients than the other (‘oligotrophic’). Two mathematical models are analyzed to estimate eutrophication differences. The second model based on the Michaelis–Menten uptake and Droop growth shows that cells in the eutrophic culture should have about 56% higher content of silica which is the limiting nutrient. Diatom samples were prepared for the transmission electron microscopy after cells have been kept in chemostats for 37 days. The structure of diatom cells was investigated and a comparison is made between cells grown in oligotrophic and eutrophic conditions. In eutrophic culture, dividing cells were encountered more frequently while cell concentration was approximately equal in both chemostats. The central vacuole of cells in eutrophic culture accumulated dispersed and compact material from amorphous to spherical shape. In some cells the large central vacuole had fibrilar and peppered dense materials in addition to translucent granules, vesicules and multivesicular bodies. In the cytoplasm we found increased number of multivesicular bodies, dense and lucent granules some of which enclose membrane particles and lucent vesicules. Dense material depositions observed in the vacuole are also seen in the cytoplasm associated with organelles, mitochondria and plasmalemma. Cells have well-developed, active and slightly increased number of dictyosomes (5–6). Some dictyosomes with dense secretory material in the cistern are apparently engaged in a granule formation process. Functional significance of dense material in the central vacuole, which has not been observed in cells grown in oligotrophic condition, is discussed.     

Optimizing electron spin resonance detection of hydroxyl radical in water

The parameters affecting the electron spin resonance (ESR) detection of hydroxyl free radical in water are studied and optimized. The hydroxyl radical is generated by the Fenton reaction with iron (II) ammonium sulfate and hydrogen peroxide reacting in a phosphate buffer using N-tert-butyl-alpha-phenylnitron as the spin trap. The concentrations of Fe²⁺, H₂O₂, and phosphate buffer are the parameters studied. The Taguchi method and the orthogonal experiment design were used to evaluate the effects of these parameters on the ESR signal intensity. By the analysis of the signal-to-noise ratio and the analysis of variance, the order of importance of the various parameters on the hydroxyl radical formation is determined for optimal ESR detection of hydroxyl radical. The results will help the development of water purification technologies using hydroxyl free radical as a green oxidant.     

微生物燃料电池中产电微生物电子传递研究进展

微生物燃料电池集产电和污水净化为一体,作为一种新型的能源回收技术得到人们的广泛关注。从微生物燃料电池工作原理来看,电子能否顺利地传递到阳极表面对于电流的产生起着关键作用。因此,本文重点阐述了电子在产电微生物体内产生的途径、电子从微生物体内向阳极传递的不同方式以及阳极材料对产电微生物附着和电子传递的影响。从生物化学、电化学和材料学上对产电微生物体内的电子到阳极整个过程进行全面的综述。明确电子传递的关键环节,为新型高效阳极材料的开发提供思路。     

电子束照射法脱硫脱氮技术工艺

在阐明电子束照射法脱硫脱氮技术的机理、流程、特点的基础上 ,探讨了该工艺在应用过程中存在的主要经济、技术问题。     

Insights into the electron transfer mechanisms of permanganate activation by carbon nanotube membrane for enhanced micropollutants degradation

● A CNT filter enabled effective KMnO₄ activation via facilitated electron transfer. ● Ultra-fast degradation of micropollutants were achieved in KMnO₄/CNT system. ● CNT mediated electron transfer process from electron-rich molecules to KMnO₄. ● Electron transfer dominated organic degradation. Numerous reagents have been proposed as electron sacrificers to induce the decomposition of permanganate (KMnO₄) by producing highly reactive Mn species for micropollutants degradation. However, this strategy can lead to low KMnO₄ utilization efficiency due to limitations associated with poor mass transport and high energy consumption. In the present study, we rationally designed a catalytic carbon nanotube (CNT) membrane for KMnO₄ activation toward enhanced degradation of micropollutants. The proposed flow-through system outperformed conventional batch reactor owing to the improved mass transfer via convection. Under optimal conditionals, a > 70% removal (equivalent to an oxidation flux of 2.43 mmol/(h·m²)) of 80 μmol/L sulfamethoxazole (SMX) solution can be achieved at single-pass mode. The experimental analysis and DFT studies verified that CNT could mediate direct electron transfer from organic molecules to KMnO₄, resulting in a high utilization efficiency of KMnO₄. Furthermore, the KMnO₄/CNT system had outstanding reusability and CNT could maintain a long-lasting reactivity, which served as a green strategy for the remediation of micropollutants in a sustainable manner. This study provides new insights into the electron transfer mechanisms and unveils the advantages of effective KMnO₄ utilization in the KMnO₄/CNT system for environmental remediation.     

The relevance of James Lovelock’s research and philosophy to environmental science and academia

James E. Lovelock, famed for his Gaia hypothesis, which views the Earth as a living integrated and interconnected self-regulating system whose equilibrium comes about from complex energy-based interactions and feedback loops, ultimately sustaining life, passed away at the end of July, 2022 at the age of 103. Not only are the adaptive mechanisms of Gaia central to the conversation of environmental homeostasis, they lie at the heart of climate change and global warming. Lovelock is also remembered as the co-inventor of the electron capture detector that eventually allowed for the sensitive detection of chlorofluorocarbons and pesticides. Finally, Lovelock’s free-spirited nature and research independence allow academia to rethink current research’s modus operandi.     

预处理方法对香蒲厌氧发酵联产H2-CH4效能的影响

通过厌氧发酵动力学分析、还原糖及其他代谢产物变化情况,结合香蒲微观结构解析,系统研究酸(HCl)、碱(NaOH)、酶(纤维素酶R-10)3种预处理对水生植物厌氧发酵联产H₂-CH₄的影响. 结果表明:香蒲分别经酸、碱、酶3种预处理后,厌氧发酵联产累积H₂、CH₄产量及含量均显著提高,c(HCl)、c(NaOH)均为1.0mol/L, w(纤维素酶R-10)(以底物计)为10mg/g时,预处理最佳. 其中1.0mol/L NaOH预处理香蒲效果最佳,φ(H₂)(H₂含量)达30.09%,累积产H₂量(以香蒲干质量计)达11.39mL/g;φ(CH₄)(CH₄含量)最高达67.48%,累积产CH₄量(以香蒲干质量计)达41.87mL/g;还原糖利用率达50.87%,sCOD(溶解性化学需氧量)利用率达66.17%. 纤维素酶预处理后香蒲产CH₄能力显著提高,产CH₄阶段φ(CH₄)最高为71.39%,累积产CH₄量达46.32mL/g,还原糖利用率达72.10%. 扫描电镜微观结构分析表明,碱预处理对香蒲纤维素结构破坏程度最大,可有效增加香蒲与微生物接触面积,有利于厌氧发酵联产H₂-CH₄工艺的快速启动和稳定运行.      

薇甘菊浸提液对福寿螺主要器官组织损伤的扫描电镜观察

采用薇甘菊（Mikania micrantha H.B.K.）的乙酸乙酯浸提液对福寿螺（Pomacea canaliculata）进行浸杀,通过扫描电镜观察福寿螺头足部、外套膜及肝脏组织的损伤状况,探讨薇甘菊化感物质对福寿螺器官组织结构的影响。经过薇甘菊质量浓度为100mg·L^-1提取液浸杀2d后,福寿螺主要器官出现了明显的组织损伤。头足部肌肉组织出现明显的杂乱丝条状并有断裂,部分有侵蚀剥落,表现为较大的组织缺损;外套膜有大量的细胞被浸润,呈疏松不整齐的结构;肝脏表面粗糙,凹凸相间的皱褶形成起伏不平的组织,其间有深浅不一的裂痕,并有侵蚀孔状损伤。扫描电镜的观察结果可为探讨薇甘菊浸提液对福寿螺的毒杀机理提供一定的依据。     

Developing “precise-acting” strategies for improving anaerobic methanogenesis of organic waste: Insights from the electron transfer system of syntrophic partners

Methanogenesis is the last step in anaerobic digestion, which is usually a rate-limiting step in the biological treatment of organic waste. The low methanogenesis efficiency (low methane production rate, low methane yield, low methane content) substantially limits the development of anaerobic digestion technology. Traditional pretreatment methods and bio-stimulation strategies have impacts on the entire anaerobic system and cannot directly enhance methanogenesis in a targeted manner, which was defined as “broad-acting” strategies in this perspective. Further, we discussed our opinion of methanogenesis process with insights from the electron transfer system of syntrophic partners and provided potential targeted enhancing strategy for high-efficiency electron transfer system. These “precise-acting” strategies are expected to achieve an efficient methanogenesis process and enhance the bio-energy recovery of organic waste.